I want to almost copy what I just wrote in another post, as I think I explained it quite decently and in a short way:

This subject is simply just too broad to cover in one reply. However to make it clear and simple, you want to separate SEO into three steps.

1. Analyze the market for relevant popular topics for your website, using Google Keyword Planner.2. Optimize your website for the keywords with following techniques. Most important from the top and down: a) Domain Name b) Website title c) Inner URL d) Headers H1, H2, H3 e) Image ALT texts f) Image GPS coordinates (for local ranking) g) Body text3. Ask stronger websites (majestic.com trustflow and moz.com domain authority) to link to yours with relevant context. Relevancy is based on the similarity between the pages that are being linked together in accordance to the parameters mentioned above for on-page SEO.

By optimize I mean adding the keywords you find in the places mentioned.

First, I will deeply review the whole website and will check the following thing:

1. Where is the target market?2. Is Website new or existing?3. Is there any Google penalty on the site?

After checking this, I will start doing on-site optimization with keyword research and will find appropriate and relevant keywords. I will also make meta tags.After on-site activities, I will move to off-site optimization.